I'm also aware that I could put an entire Debian ARM distro on the Empeg itself and compile there, but I upgrade it so often for alpha tests that I'd be re-doing the distro far to often for my tastes.
You can put it on a NFS server somewhere and mount it from the empeg, this way you won't have to rebuild it when you upgrade the empeg. I have a RedHat system set up like this but it was very painful to bootstrap since I couldn't use any of the standard installers.
Anyway, I agree with the other replies in this thread - the easiest option by far is to install Linux on a desktop machine (provided you can spare a gig or two of diskspace).
Regards,
Borislav